Method and apparatus for sealing vitreous vessels



D. S. GUSTIN Feb. 17, 1942.

METHOD AND APPARATUS FOR SEALING VITREOUS VESSELS Filed Deo. l, 1939 INVENTOR ./J. GUS'T/V.

BY www ATTORNEY Patented Feb. 17, 1942 METHOD AND APPARATUS FOR SEALING VITREOUS VESSELS Daniel S. Gustin, Bloomfield, N. J., assigner to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 1, 1939, Serial No. 307,055

(ctms- 2) 18 Claims.

This invention relates to the sealing of vitreous vessels, and more particularly to tipping oil exhaust tubes of incandescent electric lamps containing gas at a pressure higher than atmospheric.

The principal object of my invention, generu ally considered, is the tipping off of the exhaust tubes of incandescent electric lamps which have been filled with gas at a pressure of higher than atmospheric.

Another object of my invention is the provision of a method and apparatus for tipping off exhaust tubes While enclosed in a space, dened by a reentrant nare tube and a closure member including electrodes for effecting the tipping oil operation.

A further object of my invention is the employment of high frequency electric power for tipping off the exhaust tubes of vitreous vessels.

A still further object of my invention is the tipping off of exhaust tubes of incandescent electric lamps short of the iiare tube opening of such lamps, whereby there is no sharp projecting portion of said tube outside of the lamp bulb outline after completion.

Other objects and advantages of the invention, relating to the particular arangernent and construction of the various parts, will become apparent as the description proceeds.

Referring to the drawing:

Fig. 1 is an elevational view of a lamp conconstructed in accordance with my invention, with portions broken away to more clearly illustrate the interior construction.

Fig. 2 is an enlarged sectional View of the flare tube and neck portion of a lamp as shown in Fig. 1, with apparatus in place for eecting the operation of tipping off the exhaust tube of said lamp, the power supplied being diagrammatically indicated.

Fig, 3 is a transverse sectional view on the line III-III of Fig. 2 in the direction of the arrows.

In my copending application, Ser. No. 144,143, led May 22, 1937, now Patent No. 2,213,100, granted September 17, 1940, and owned by the assignee of the present application, I describe a method and machine for sealing vitreous vessels which contain gas at a pressure higher than atmospheric, in a manner which prevents the exhaust tube from blowing out during the tippingoff operation. In that case I provide a special chamber which is disposed about a portion of the exhaust tube, and in which a pressure above atmospheric, or corresponding with the pressure in the lamp, is provided and the sealing ofi is effected by means of gas fires in said chamber.

In accordance with my present invention, I eliminate the necessity for such a special pressure chamber for such a purpose, by using the flare tube of the lamp itself, merely closing off the open end thereof and providing electrodes which extend into said flare tube and upon which suitable electric power is impressed, whereby the tube is not only sealed off under pressure, but the tip is made inwardly of the are tube opening, thereby avoiding the undesirable projection of a relatively sharp portion beyond the flare tube.

The electric power employed is preferably ultra high frequency, say from ten to sixty megacycles, at a potential of k. v., whereby the dielectric loss in the tube disposed between the adjacent ends of electrodes will serve to soften it sufiiciently for the tipping-off operation. However, other electrical heating means, such as that due to resistance, may be employed instead.

Referring to the drawing in detail, like parts being designated by like reference characters, there is shown a gas-filled lamp II, comprising a vitreous or glass envelope I2, having a reduced, generally cylindrical, neck portion I3, to which is sealed the usual nare tube I4, from the press I5 of which extends an arbor I6, and supporting leads Il and 8, between which extends a tungsten larnent I9 which, in the present embodiment, is of the coiled coil type. The arbor i6 is shown with a button 2| from which extend bracing wires 22 and 23 to the leads Il and I8, and a supporting wire 24 to the filament I9.

In Fig. 1 the lamp I I is shown provided with a medium screw base 25, and the exhaust tube 2S thereof is shown terminating short of the opening 2l to the reentrant portion provided by the flare tube I4,

Referring now to Figs. 2 and 3, the flare tube opening, 2l is shown closed by apparatus 20, including resilient gasket means 28, preferably formed of rubber, and slidable electrodes 29 and 3i provided with their adjacent end portions 32 and 33 extending diagonally through a corresponding aperture in the gasket 28 into the chamber, defined by said closure apparatus and the flare tube I4, and engaging opposite sides of the exhaust tube 26, at a point sufficiently remote from the gasket 28 that the localized heating provided will not cause injury thereto, during the short period of time needed for the tipping off of said exhaust tube. The lower end of the exhaust tube 2B is shown received in a compression rubber 34, coresponding with that designated by the reference character I2 in my copending application, previously referred to.

The closure device 20 deslrably comprises arms 30 and 40 pivoted in a manner disclosed in the Holloway application, Ser. No. 297,089, iiled Sept.

29, 1939, and owned by the assignee of the pres- I ent application, and operated by means of a lever, not shown, corresponding with that designated 44 in said application, so that said arms may be separated in order to permit reception of the exhaust tube 26 between the end portions thereof, notched as indicated'at 53, and allow lfor the separation of the electrodes 29 and 3| for the same purpose.

'I'he electrodes 29 and 3i are movable toward and away from one another in suitable slots, 35 and I8, one in each of the closure parts 3D and lll, the fit therein being sufficiently close to avoid any substantial leakage of air thereby. In order to urge said electrodes into engagement with the exhaust tube 2B, after the ends of the parts have been brought togethensprings 31 and 38 are provided acting between shoulder portions formed by depending flanges of angular clips 3S and 4I, secured to the electrodes, and correspond ing upstanding flanges I2 and 43 of angular portions secured to the closure parts 30 and 4D.

The portions 38 and 4i on the electrodes are normally spaced from corresponding stop sur faces 44 and 45 on the closure parts 3u and 40 so that they can move together the desired amount for sealing off an exhaust tube 26, but will not move into actual contact with one another. The electrodes 29 and 3i are connected to a suitable source of power, represented by the secondary winding I6 of transformer 41, by means of leads 48 and 49, said power being prei erably ultra high frequency of more than ten megacycles, and preferably of the order of nity megacycles, at a potential of about 100 kilovolts.

The mode of operation of tipping off a lamp, when disposed as shown in Figs. 2 and 3, is to effect an exhaust and filling of the bulb l 2 there of, with the desired inert gas, as described more in detail in my copending application previously referred to, through the exhaust tube 26. After being filled with inert gas to the desired superatmospheric pressure, the arms 3U and 4l) are brought together to engage the tube 26, as shown in Figs. 2 and 3, and compressed air is admitted to the chamber 5i defined by the flare tube Il and the closure parts 30 and 40, as by means ci' tube 52, until the pressure in said chamber ap proximates, or preferably exceeds, that in the bulb I2. The exhaust tube 2S passes through i the notched portions 53 in the closure apparatus 20 with small enough clearance, so that there is relatively little leakage out of the chamber 5I.

Ultra high frequency electrical energy is then impressed on the electrodes 29 and 3|, causing a heating of that portion 54 of the exhaust tube immediately between the engaged ends 32 and 33 of said electrodes, either due to the dielectric loss in said tube, previously referred to, or a discharge or arc between said electrodes which may envelop that portion of the tube therebetween, or to more than one of these actions, depending on the voltage, frequency and conductivity of the tube, whereby said exhaust tube portion rapidly softens and is squeezed to effect a tipping olf thereof by inward movement of the electrodes 29 and 3l under the influence of the actuating springs 31 and 3B. When this has been effected, the tipped-on lamp is removed, either by the opfifi erator, or automatically as described in the Holloway application previously referred to.

Although a preferred embodiment of my in. vention has been disclosed, it will be understood that modiiications may be made within the spirit and scope of the appended claims.

I claim: Y

1.1The method of sealing a vitreous vessel having an exhaust tube extending from a reentrant portion, comprising closing said reentrant portion around said tube, creating a gas pressure above atmospheric in said closed space. and electrically tipping on at a portion of said tube while subjected to said pressure.

2. The method of sealing a vitreous vessel, having an exhaust tube extending from a reentrant portion, comprising disposing electrodes so that their adjacent ends engage said exhaust tube inwardly of the open end of said reentrant portion, creating a gas pressure above atmospheric around said engaging ends, and energizing said electrodes by means at high frequency to tip off said exhaust tube inwardly of said opening.

3. Thernethod of sealing a vitreous vessel, having an exhaust tube extending from a reentrant portion, comprising disposing electrodes so that their adjacent ends engage said exhaust tube inwardly of the open end of said reentrant portion, creating a gas pressure above atmospherc in said reentrant portion, and energizing said electrodes to tip oir said exhaust tube.

4. The method of sealing a vitreous vessel having an exhaust tube extending from a reentrant portion, comprising closing said reentrant portion around said tube by means including electrode portions extending into said reentrant portion, admitting compressed air to said reentrant portion around said electrodes and tipping off by applying electrical energy to said electrodes.

5. The method of sealing a vitreous vessel having a tubular extension from a reentrant portion, after said vessel has been filled with a gasl above atmospheric pressure, comprising closing said reentrant portion around said extension, creating gas pressure above atmospheric in said reentrant portion, and tipping ofi the enclosed portion of said extension while subjected to said pressure.

6. The method of sealing off a lamp having an exhaust tube extending from a reentrant portion, comprising closing said reentrant portion around said tube by means including electrode portions engaging said tube in said reent'rant portion, exhausting, and filling said lamp through said tube with gas above atmospheric pressure, creating in said reentrant portion a gas pressure at least as high as that in said lamp, and applying high frequency energy to said electrodes to eifect a tipping-oif operation iin said reentrant portion.

7. Apparatus for tipping off exhaust tubes eX- tending from reentrant portions of vessels containing gas at a pressure higher than atmospheric, comprising closure means for said reentrant portions, including electrodes the adjacent ends of which extend into said reentrant portions, means for creating a gas pressure above atmospheric in said reentrant portions, and means for applying electrical energy to said electrodes to effect a tipping-oir operation.

8. Apparatus for tipping off exhaust tubes extending from reentrant portions of vessels containing gas at a pressure higher than atmos pheric, comprising closure means for said reentrant portions including electrodes, said closure means being formed as end portions of pivoted arms, whereby it is adapted to encircle an exhaust tube, with the electrodes engaging opposite sides thereof in a. reentrant portion, means for creating a gas pressure above atmospheric in said reentrant portion, and means for applying electrical energy to said electrodes to effect a tipping-off operation.

9. Apparatus for tipping off an exhaust tube extending from a reentrant portion Vof a vessel containing gas at a pressure higher than atmospheric, comprising closure means for said reentrant portion; including resilient gasket means adapted to engage the adjacent end of said Vessel, a pair of electrodes slidable in said closure means and having their adjacent portions extending diagonally through an aperture in said -gasket means to engage said exhaust tube on opposite sides thereof, means for creating a gas pressure above atmospheric in said reentrant portion and means for applying electrical energy to said electrodes to effect a tipping-ofi' operation.

10. Apparatus for tipping oil? 'an exhaust tube y extending from a reentrant portion of a vessel,

comprising closure means yfor holding gas pressure in said reentrant portion, a pair of electrodes slidable in said closure means and having their adjacent portionsextending diagonally toward one another and into said reentrant portion to engage said exhaust tube on opposite sides thereof, and means for eiecting a tipping-off operation therein by means of ultra high frequency electrical energy.

11. The method of sealing vitreous vessels having an exhaust tube extending in a reentrant portion, comprising creating a gas pressure above atmospheric in said reentrant portion and electrically tipping off said tube in said reentrant portion while subjected to said pressure.

12. The method of sealing a vitreous vessel having a tubular extension in a reentrant portion, comprising creatinggas pressure above at-l mospheric in said reentrant portion and tipping oi! said extension in said reentrant portion while subjected to said pressure.

13. Apparatus for tipping off exhaust tubes extending in reentrant portions of vessels containing gas at a pressure higher than atmospheric, comprising means for creating'a gas pressure higher than atmospheric in vsaid reentrant portions, and means for tipping o!! said exhaust tubes at points within said reentrant portions while subjected lto said pressure.

14. Apparatus for tipping off exhaust tubes extending from reentrant portions of vessels containing gas at higher than atmospheric pressures, comprising means for closing said reentrant portions, means for creating a gas pressure above atmospheric in said closed portions, and means for applying energy to said exhaust tubes in said reentrant portions for effecting tipping-off operations.

15. The method of sealing a vitreous vessel having an exhaust tube, comprising enclosing only a portion of said tube in a chamber, creating a gas pressure above atmospheric in said chamber, disposing electrodes with their adjacent ends engaging opposite sides of a portion of said tube in said chamber, and causing an electrical y discharge between said electrodes to heat said tube for tipping it off therein.

16. The method of sealing a vitreous vessel having an exhaust tube comprising enclosing only a portion of said tube in a chamber disposed close .to said vessel and defined in part by wall portions thereof, creating gas pressure above atmospheric in said chamber, disposing electrodes with their adjacent ends engagin opposite sides of a portion of said tube in said chamber, and causing an electrical discharge between said Ielectrodes to heat and tip off the tube therein.

17. The method of sealing a vitreous vessel having an exhaust tube comprising enclosing only a portion of said tube in a chamber, creating a gas pressure above atmospheric in said chamber, disposing electrodes withtheir adjacent ends dir rected toward said vessel, so as to engage opposite sides of a portion of said tube close'to said vessel and insaid chamber, and causing an electrical discharge between said electrodes to heat said tube and tip it oif in v-said chamber, leaving only a short length on said vessel.

18. The method of sealing a vitreous vessel having an exhaust tube comprising enclosing only a portion of. said tube in a chamber defined in part by wall portions of said vessel, creating a gas pressure above atmospheric in said chamber, disposing tipping off elements with their adjacent ends directed toward said vessel, so as to engage oppositesides of a portion of said tube in said chamber and disposed close to said vessel, and applying heat to said vexhaust tube by means of said elements to tip it oi in said chamber andleave only a short length on said vessel.

DANrsL' s. Gus'rm. 

